Manufacture of thymol



FRITZ G'llNTHER, 0F LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNQE TUEA'DISGHE ANILIN- 5 SODA-FABRIK, 0F LUDWIGSHAEFENf-ON EHE-JRHINE,GENE-ANY, A CORPORATION OF GERMANY.

TEAN'UFACTURE 0F THYTJIOL.

No Drawing.

T 0 all w 710m it may concern Be it known that l, FRITZ GiiN'rr-rna,citizen of Germany, residing at Ludwigshafen-on-the-Rhine, Germany, haveinvented new and useful Improvements in the Manufacture of lhymol, (forwhich 1 have made application in- Germany, No. B. 94,890, IV 112 q.,July 3, 1920,) of which the following is a specification.

The invention relates to a process for the synthetic manufacture ofthymol (l-methyl- 4-isopropy1-3-hydroxybenzene) which is very simple andwhich can also be carried out on a commercial scale. This processconsists in sulfonating meta-cresol, treating the meta-cresol-sulfonicacid so obtained with isopropyl-alcohol and sulfuric acid, preferablyeffected at a raised temperature and with the sulfuric acid concentratedand finally splitting oil the sulfonic group in the usual, or anysuitable manner. The thymol which is obtained by distillation is solublein caustic soda lye either completely or with the exception of verysmall traces.

In order to further explain the nature of my invention, 1 give thefollowing example, but the invention is not limited thereto. The partsare by weight.

Ewa/mple.

875 parts of monohydratic sulfuric acid are gradually introduced into540 parts of meta-cresol, care being taken that the temperature does notexceed about 100 degrees centigrade. After all of the monohydrate hasrun in, the mixture is kept at 100 degrees centigrade for two hours,then cooled- Specification of Letters IPatent.

Patented Apr. 18., $322.

Application filed August 19, 1921. Serial No. 193,713.

mixed with 1750 parts of water and distilled with steam at from 120 to130 degrees centigrade, whereby the sulfonic group is split otf andthymol distilled over with the water vapor. The oil obtained is workedup in the usual manner and can be separated from small traces ofisopropyl-ether compounds, for example bymeans of caustic alkali. lheproduct is subjected to fractional distillation, preferably in vacuo,and separated thereby from first-runnings consisting of unalteredmeta-crcsol and afterrunnings containing a product crystallizing frombenzene in splendidly formed large odorless crystals, melting at 114415degrees centigrade and very likely representmg a thymol-isomcr, whilstthe middle fraction, when cooled and inoculated with a thymolcrystal,soon solidifies to a crystalline mass, which, if necessary, can easilybe purified further for example from ligroin by recrystallization.

T he melting point of the synthetic product obtained according to thisinvention is -51 degrees centigrade.

I claim 2- 1. The process of manufacturing thymol synthetically whichconsists in treatin r sulfonated meta-cresol with isopropyl-a cohol andstrong sulfuric acid, then splitting off the sulfonic group.

2. The process of manufacturing thymol synthetically which consists intreatin sulfonated mcta-cresol with isopropyl-all-ohol and strongsulfuric acid, then splitting off the sulfonic group by heating withsulfuric acid ,and water.

my hand.

FRITZ GUNTHER.

